Reconnaissance/surveillance system utilizing color signature of target

Abstract

A photo-reconnaissance/surveillance system in which the landscape to be scanned is photographed on color film. The film is then developed in a highspeed processor and scanned by photosensors. Illuminations for the sensors is provided by a plurality of point sources of light. Colored filters e.g., a green filter and a blue filter, are alternately interposed between the light sources and the film. A logic circuit compares the transmission through the film for both light conditions and, thus, can detect the presence of a target, if the color signature of the target is known a priori.

What I claim is: 
     
       1. Apparatus for detecting a target of known color signature and locating its position, which comprises: film-supply means to continuously supply a color-sensitive photographic film;   a camera downstream of said film supply means to photograph onto said film successive portions of a scene suspected of containing said target;   film processing means downstream of said camera to continuously process the exposed film using a rapid color processing technique;   examining means downstream of said film processing means, comprising light source means, a bank of photoreceptors, and analyzing means, with said film passing between the light source means and the bank of photoreceptors; wherein the light source means includes spectral selection means to supply light of at least two different spectral contents, the photoreceptors are connected to supply electrical output signals to the analyzing means, the analyzing means uses said output signals for successive regions of the film to form detected color signatures thereof comprising the ratio of the output signals therefrom for light of at least two different specified color components thereof, and the analyzing means further compares said detected color signatues with stored data for said known color signature and provides a given indication in response to finding a match within predetermined limits.   
     
     
       2. The apparatus according to claim 1 wherein said film is color negative film. 
     
     
       3. The apparatus according to claim 1 wherein said film is color reversal film. 
     
     
       4. The apparatus according to claim 1 wherein said film is infra-red sensitive color film. 
     
     
       5. The apparatus according to claim 1, wherein said spectral selection means comprises means for alternately inserting filter elements of a first and a second color between light sources and said photoreceptors, and further includes means to synchronize and inserting means with the operation of the analyzing means. 
     
     
       6. Apparatus according to claim 1 for use in an aerospace vehicle which includes navigation equipment producing coded data identifying its location and other information, and wherein said camera includes means coupled to the navigation equipment to provide code marks on said color film corresponding to said coded data. 
     
     
       7. The apparatus according to claim 5 wherein said inserting means comprises: a rotatable disc having at least two segments of differing filter material; and   means for rotating said filter disc in the path of said light sources.   
     
     
       8. A method of detecting a target of known color signature comprising continuous processing with color-sensitive film between a supply reel and a take-up reel including the steps of: photographing on said color film successive portions of a scene suspected of containing said target;   processing said color film;   alternately illuminating successive regions of said color film with light of at least two different wavelength bands, said light being received by a plurality of photoreceptors;   analyzing electric signals from said photoreceptors and computing color signatures comprising the ratio of light represented by the electric signals for at least two different specified color components for each region;   and comparing the color signatures with stored data for said known color signature and providing a given indication in response to a match within predetermined limits.   
     
     
       9. The method according to claim 8 wherein said illuminating step comprises: directing a plurality of discrete light sources onto said film; and then   positioning a rotating filter disc between said light sources and said film, said disc including at least two filter segments of differing filtration characteristics.   
     
     
       10. The method according to claim 8 including the further step of: coloring the military vehicles, armament, et cetera, of friendly forces such that a predetermined color signature is obtained therefrom; and then   in said color ratio computing step, ignoring targets having a color signature which corresponds to said predetermined color signature.   
     
     
       11. The method according to claim 8, including the further step of transmitting via electronic means to another location a copy of the photograph containing said region producing said given indication. 
     
     
       12. A method of detectng a target of known color signature, wherein successive portions of a scene suspected of containing said target have previously been photographed onto color-sensitive film, and the color film has been processed to provide color photographs of said scene, said method comprising the steps of: alternately illuminating successive regions of said color film with light through two filters passing two different wavelength bands, said light being received by a plurality of photoreceptors;   analyzing electric signals from said photoreceptors and computing color signatures comprising the ratio of light represented by the electric signals for at least two different specified color components for each region;   and comparing the color signatures with stored data for said known color signatures and giving an indication in response to a match within predetermined limits.   
     
     
       13. The method according to claim 12, wherein said color photographs include code marks derived from navigation equipment and placed on the film when the scene was photographed, and the method includes the stop of using said code marks to identify the location of the target.